A distribution center for a set of products is a warehouse or other specialized building, often with refrigeration or air conditioning, which is stocked with goods to be redistributed to retailers, to wholesalers, or directly to consumers. Distribution centers are the foundation of a supply network, as they allow a single location to stock a vast number of products. Some organizations operate both retail distribution and direct-to-consumer out of a single facility, sharing space, equipment, labor resources, and inventory as applicable. Distribution centres are typically very large installations, often providing upwards of one million square feet of storage space at a single location. In order to efficiently manage the placement, storage and retrieval of products, specially designed push back storage racking systems are constructed. Typically racking systems are constructed with capacity to hold (4) four to six (6) pallets deep and in tiers to hold multiple pallets in height. The racking systems typically have a multi-level steel beam framework which supports platforms upon which pallets of goods are stored. Individual pallets of goods are accessed using lift trucks. Access to particular pallets of goods can only be achieved from the exposed end of the rack. Different types of racking systems have been developed to optimize product selection and retrieval and/or to permit high density storage.
One such racking system is known as a “push back rack”, shown in FIG. 1. Such systems combine high density storage with versatility. The system operates on the last in, first out (LIFO principle) and provides multiple lanes of pallet storage, each of which flow independently. As best seen in FIG. 2, in a push back rack system product pallets are placed by forklift on nested trays riding on inclined rails. Each pallet is then pushed back by subsequent pallet loading, exposing the next nested tray. When removing product, the forklift takes out the front pallet, allowing the pallets on trays behind it to roll gently (gravity fed) to the front of the rack. The nested trays make it easier to place and retrieve pallets. The operator of the forklift or lift truck does not have to enter the racking framework, instead accessing the pallets from the front of the rack. A push back rack system fills the storage area with product, not aisles. It is not necessary to maintain open aisles between each row of pallets. Instead, the nested racks in the push back rack system allow pallets to be stored up to 6 deep on the nested rack trays which roll on the inclined rails. The push back rack systems can be placed back to back thereby making it possible to store up to 12 pallets depth, with 6 pallets accessible from the front and the other 6 accessible from the back.
Typically the push back rack systems are constructed using “I” beam rails which are attached to the stacked support beams. A plurality of rack trays are mounted to the rails in nested fashion. A safety bar is provided for the last pallet stored on the rails in order to prevent a tray rolling forward off the rails and into the aisle below.
One difficulty which can occur with push back rack systems relates to rack jams. Occasionally the wrapping around goods on a pallet will become damaged and product will become dislodged from pallets. This phenomenon is illustrated in FIG. 3. With high density racking systems the dislodged products will spill into surrounding storage racks, and can become jammed in the rails or between rack trays, causing seizure of the rack trays.
At present the options for clearing jammed racks are very limited. It is extremely dangerous for an individual to attempt to climb into a racking system. Since pallets are stacked multiple rows high, the risk of a person falling while trying to access a jam is very grave. A bridge mounted to a forklift can be used to reach a short way into a racking structure to allow an individual to walk into a lane in a rocking system in order to clear jams which are close to the front. This approach cannot be used to clear jams which are located farther back in a storage lane.
Often existing jammed rack locations simply cannot be cleared safely. When jams cannot be cleared, a section of the rack must be taken out of service and cordoned off, with the result that storage capacity is lost and the profitability of the distribution centre is decreased. If storage rack locations are out of service for extended periods of time the products stored at or behind the site of the jams may expire and no longer be saleable. Product expiration results in lost revenue from the unsaleable products, and additional incurred costs to dispose of the expired product.
At present, there is no commercially available equipment that would enable operators to safely perform repair, maintenance or inspection operations of a pushback rack system or the surrounding rack structure at height
It is an object of the present invention to provide a safe and economical solution for clearing rack jams.
It is yet a further object to provide a device which can be utilized to permit the safe and efficient inspection, maintenance and repair of push back rack systems.
It is yet another object of the present invention to provide a shelter which can be adjusted in size to accommodate a variety of stored items and to adjust to cramped spaces.